Word: bypass
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...preliminary study that lacked a control or comparison group. "I think there's something to this," says Dr. Patrick McCarthy, a cardiac surgeon at the Cleveland Clinic. But he is quick to add that it's not at all clear how much of the decline is due to the bypass and how much to aging...
Still, it's not difficult to imagine how a bypass operation could cause brain damage. During most procedures, the heart is actually stopped for as long as two hours while a heart-lung machine takes over the job of oxygenating the blood and pumping it through the body. Studies have shown that microscopic bubbles of air or tiny bits of fat and plaque are often loosed into the bloodstream in the process. Even if they are too small to trigger a full-scale stroke, they may cause minor damage in the cerebral tissue...
Doctors are already exploring ways to make bypass operations easier on the brain. Some surgeons, for example, try to minimize the risk of shaking loose a clot by scanning the aorta with ultrasound for plaque-free regions at which to attach the heart-lung machine. Another option being tested in the U.S. is to stick a filter into the aorta to catch any wayward debris...
Most ambitious of all is a new type of bypass procedure that allows surgeons to operate directly on a beating heart without having to resort to a heart-lung machine. Such off-pump surgery requires great technical skill, however, and isn't an option for everyone. (The best candidates have stable heart function and discrete, easily accessible blockages.) Still unknown is whether off-pump grafts last as long as conventional ones or even if the operation makes any real difference to the brain...
...England Journal study has highlighted one of the drawbacks of bypass operations, but even its authors say that they hope it doesn't scare anybody away from getting necessary surgery. They note that many of the study participants wouldn't have lived five years without the operation. To them, a little trouble with memory or attention might seem worth...